Lightning arrester



March 7, 1939. G. E. ANDRE 2,149,327

LIGHTNING ARRESTER Filed Dec. 7, 1934 Patented Mar. 7, 1939 UNITED STATES,

LIGHTNING ABRESTER Gustaf E. Andre, Richmond, Ind., asslgnor to Belden Manufacturing Company, Chicago, 111., a corporation of Illinois Application December '1, 1934', Serial No. 156,449

3 Claims. (01. 175-30) This invention relates to improvements in lightning arresters and has for its main object the provision of a substantially weather proof and highly eflicient lightning arrester which may be produced and sold at a very low cost. Another object is to provide a small sized compact lightning arrester of comparatively light weight so that it may readily be supported solely by wires to which it is attached and without attachment It) to any other support. Generally, it is the object of the invention to provide an improved lightning arrster designed mainly for the protection of radio apparatus, although not restricted thereto.

Other objects and advantages of the invention will be understood by reference to the following specification and accompanying drawing, in which there are illustrated lightning arresters embodying two selected forms of the invention.

In the drawing Fig. 1 is a longitudinal sectional view through the axis of the device;

Fig. 2 is an end elevation of the structure shown in Fig. 1;

Fig. 3 is a longitudinal sectional view through the axis of another form of the device; and

Fig. 4 is an end elevation of the srtucture shown in'Fig. 3.

Referring now to the drawing, the form of lightning arrester shown in Figs. 1 and 2 consists of a main casing or housing 5 preferably formed of porcelain or some other suitable insulating material. The casing 5 is of tubular formation, preferably cylindrical, and is provided intermedietc its ends, with a portion designated 6, of a predetermined internal diameter. At the opposite ends of the intermediate portions 6, there are portions designated 1 and 8 respectively, of an enlarged internal diameter.

Oppositely disposed terminal members 9 and Ill-respectively enter the casing 5 from its opposite ends and these terminals are preferably screw-threaded over their entire lengths, as indicated. The external diameter of the terminals 9 and I0 is preferably such as to fit snugly within the intermediate portion 6 of the casing.

The inner ends of the terminals 9 and ID are disposed in spaced relation and a quantity of silicon-carbide, carborundum, or other suitable,

preferably powdered or granular material indicated at H, is trapped between the ends of the terminals in said intermediate casing portion.

In the production of the lightning arrester, the carborundum or other material I l is subjected to compression between the terminals 9 and I0 is connected by means of a wire to a ground and the terminals are then. sealed or anchored to the casing so as to permanently hold the resistance material ll under compression.

In'the form of construction shown in Fig. l,

the terminals 9 and in are anchored in the said relation by means of suitable insulating com-' pound filler or blocks such as indicated at l2 and I3 respectively, which are molded in place in the enlarged end portions 1 and 8 of the casing. The fillers I2 and I3 may consist of any suitable sealing compound, for example, Bakelite cement or porcelain cement. Such sealing compounds effectively' interlock with the screwthreaded terminal members and with the casing walls so as to thereby hold the terminals in said compressing relationship to the resistance material ll. The lightning arrester is completed by positioning cupped washers l4' and I5 and nuts I6 and H on the projecting portions of the terminals 9 and I O'respectively.

In mounting the lightning arrester in actual service, one end (either end) is clamped on an aerial wire, for example, and the opposite end connection. Inasmuch as the lightning arrester 25 is of small size and of light weight, no support other than the aerial wire is required for the device.

In the drawing, the illustrations Figs. 1 and 3 are approximately two times the full size of a commercial device. The cupped washers l4 and I5 are preferably provided with a notch such as indicated at it inthe flange thereof, for facilitating the poistioning of the wire around the terminal and under the nut.

The structure shown in Fig.3 is substantially similar to that shown in Fig. l, and corresponding parts have been similarly numbered. However, the means ior anchoring the terminals is somewhat difierent, and in this case consists in end caps such as designated l9 and 20 which inclose the opposite ends of the casing 5. These caps may conveniently be made of lead or white metal and they are molded in place in suitable forms. To provide an adequate interlock between the caps l9 and 20 and the casing 5, the latter is provided with grooves or recesses such as indicated at 2| and 22 adjacent its opposite ends, and in this instance, the grooves 2| and 22 are illustrated as being continuous grooves around the entire circumference of the casing 5. Hence in the molding of the caps l9 and 20, small rib formations designated Iii and 2|! respectively, will be formed as an integral part of the respective end caps l8 and20. The said ribs of course are disposed in the grooves 2| and 22 andserve to interlock the end caps with the casing 5. The material of which the end caps is formed also 6 flows into intimate contact with the threaded 15 elements are molded in place in the manner explained, they very tightly fit the various parts and hence result in a substantially impervious or moisture proof construction. Such moisture proof construction facilitates the use of granu- 20 lated resistance material such asabove men tioned for lightning arrester purposes and this is highly desirable, inasmuch as granular material under compression and free from various forms of combining cement (as actually used in forming .25 resistance material blocks, etc.) aifords a greater efiiciency and increased durability, as compared with conventional lightning arresters embodying molded resistance material elements.

Changes in the described structure may be 80 made without departing from the spirit of the invention, the scope of which should be determined by reference to the following claims, the same being construed as broadly as possible consistent with the state of the art. 85 Iclaim:

1."I'he method of manuiacturing'a lightning arrester which consists in placing a predetermined quantity of a suitable granularmaterial within a tubular insulating casing, introducing a n rod-like terminal into either end of the casing,

continuously biasing the terminals toward each.- other with a predetermined force so as to subject the granular material to a predetermined compressive stress throughout the manufacturing operation, and then casting a suitable end portion on either end of the casing-while said terminals are biased toward each other, said end portions thereby serving to seal both ends of the casing and to anchor said terminals so as tomaintain the granular materialunder said predetermined compressive stress.

2. The method of manufacturing a lightning 10 arrester which consists in placing a predetermined quantity of a suitable granular material within a tubular insulating casinghaving a generally uniform bore, introducing a rod-like me-- tallic terminal into either end of the casing, continuously biasingthe terminals toward each other with a predetermined force so as to subject the granular, material to a predetermined compressive stress throughout the manufacturing operation, and then while said terminals are biased toward each other casting a suitable metallic cap upon either endof the casing in such manner that each of the caps serves to seal one end of the casing and rigidly supports one of said terminals upon the casing, thereby maintaining saidgranular material under said predetermined stress.

3. The method of manufacturing a lightning arrester, which consists in placing a predetermined quantity of a suitable granular material within a-tubular insulating casing which is open at either end thereof, placing a terminal within each of saidopenings to confine said granular material therebetween, biasing said terminals toward each other so as to subject said granular material to a predetermined compressive stress, and finally sealing the open ends of said casing and locking said terminals in place while said granular material is subjected to said stress by molding a suitable end portion on each end of said casing while said terminals are biased toward each other.

GUSTAF E. ANDRE. 

